Carved stone balls are a curious type of artifact found at a number of locations in Scotland. They date from the late Neolithic period, around 4,000 years ago. They are round in shape; they were carved from several types of stone; most are about 70 mm in diameter; and many are ornamented to some degree. Archaeologists do not agree about their purpose and meaning, but there are several theories. One theory is that the carved stone balls were weapons used in hunting or fighting. Some of the stone balls have been found with holes in them, and many have grooves on the surface. It is possible that a cord was strung through the holes or laid in the grooves around the ball. Holding the stone balls at the end of the cord would have allowed a person to swing it around or throw it. A second theory is that the carved stone balls were used as part of a primitive system of weights and measures. The fact that they are so nearly uniform in size – at 70 mm in diameter – suggests that the balls were interchangeable and represented some standard unit of measure. They could have been used as standard weights to measure quantities of grain or other food, or anything that needed to be measured by weight on a balance or scale for the purpose of trade. A third theory is that the carved stone balls served a social purpose as opposed to a practical or utilitarian one. This view is supported by the fact that many stone balls have elaborate designs. The elaborate carving suggests that the stones may have marked the important social status of their owners.
None of the three theories presented in the reading passage are very convincing.First, the stone balls as hunting weapons, common Neolithic weapons such as arrowheads and had axes generally show signs of wear, so we should expect that if the stone balls had been used as weapons for hunting of fighting, they too would show signs of that us. Marry of the stone balls would be cracked or have pieces broken off. However, the surfaces of the balls are generally well preserved, showing little or no wear or damage.Second, the carved stone balls maybe remarkably uniform in size, but their masses vary too considerably to have been sued as uniform weights. This is because the stone balls were made of different types of stone including sandstone, green stone and quartzite. Each type of stone has a different density. Some types of stone are heavier than others just as a handful of feathers weighs less than a handful of rocks. Two balls of the same size are different weights depending on the type of stone they are made of. Therefore, the balls could not have been used as a primitive weighing system.Third, it's unlikely that the main purpose of the balls was as some kind of social marker. A couple of facts are inconsistent with this theory. For one thing, while some of the balls are carved with intricate patterns, many others have markings that are extremely simple, too simple to make the balls look like status symbols. Furthermore, we know that in Neolithic Britain, when someone died, particularly a high-ranking person, they were usually buried with their possessions. However, none of the carved stone balls have been actually found in tombs or graves. That makes it unlikely that the balls were personal possessions that marked a person's status within the community.
The author in the reading passage explores three major functions of the carved stone balls. However, in the lecture, the professor respectively contradicts all his assertions by using three specific points as supports. First, even though the reading passage suggests that the stone balls were weapons because of the holes and grooves on their surface, the professor argues that the stone balls didn’t show signs of use, which means they are neither cracked nor broken and thus cannot be used as weapons. Second, despite the statement in the reading passage that the stone balls were used as primitive weighing system due to their uniform size, the professor contends that their masses vary too considerably from each other. Therefore, the balls could not function as weighing system. Third, the author asserts that the stone balls served a social purpose owing to their elaborate designs while the professor proves that this claim is indefensible by pointing out that the balls were carved with not only intricate patterns but also simple ones, besides, none of the balls were found in the ancient tombs or graves. Consequently, it’s impossible that the balls were social markers.